Substrate Holding State Detection Using Peripheral Edge Imaging

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Solution Overview

Problem

Existing substrate processing apparatuses face issues in accurately determining substrate holding due to low reflectivity caused by material or surface conditions, leading to potential erroneous determinations of improper holding.

Innovation Solution

Incorporating a camera to photograph the peripheral edge portion of the substrate when held by the substrate holding unit and using a control unit to determine the holding state based on the image, measuring distances between the substrate edge and surrounding components, and comparing these with predetermined values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If laser light reflection detection is used to determine substrate holding state, then the detection method is simple, but the measurement precision deteriorates when substrate reflectivity is low

Engineering Contradiction:

Improvedetection method simplicityVSAvoidholding state detection accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces the optical reflection detection system with a camera-based imaging system. Instead of using laser light reflection to determine substrate holding state, the system captures images of the substrate peripheral edge and analyzes the position of the substrate relative to the holding unit through image processing, thereby eliminating the measurement precision issues caused by low substrate reflectivity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a camera as an intermediary device between the substrate and the detection system. The camera captures visual information of the substrate peripheral edge, and image processing algorithms analyze this visual data to determine holding state, serving as a mediator that converts physical position information into detectable image signals without being affected by substrate material properties.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Loss of time

If light receiving device is used to detect substrate holding, then the detection process is quick, but reliability deteriorates due to erroneous determination from low light reflection

Engineering Contradiction:

Improvedetection process speedVSAvoidholding state determination accuracy

Core Design Contradiction:

Loss of timeVSReliability

Solution Approach 1:

The patent substitutes the light receiving device with a camera-based imaging and image processing system. The camera rapidly captures images of the substrate peripheral edge, and image processing algorithms quickly analyze the substrate position relative to the holding unit, maintaining fast detection speed while eliminating erroneous determinations caused by low light reflection from substrates with low reflectivity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates a visual copy (image) of the substrate peripheral edge and its position relative to the holding unit. This image copy is then processed to determine holding state, allowing the system to accurately assess substrate positioning without relying on optical reflection properties that vary with substrate material and surface conditions.

Inventive Principle:

Principle #26Copying

3Device complexity

If laser reflection method is used, then the apparatus structure is simple, but measurement precision worsens due to influence from substrate material and surface conditions

Engineering Contradiction:

Improveapparatus structure simplicityVSAvoidholding state detection accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces the laser reflection detection apparatus with a camera-based imaging system. The camera captures images of the substrate peripheral edge and holding unit, and image processing algorithms analyze these images to determine holding state. This substitution eliminates the measurement precision problems caused by substrate material and surface condition variations while maintaining relatively simple apparatus structure.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a camera as an intermediary that captures visual information of the substrate and holding unit. This image-based intermediary approach allows the system to determine holding state based on the visual position relationship between substrate and holding unit, rather than relying on optical reflection properties that are influenced by substrate material and surface conditions.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS9039863B2Substrate processing apparatus, substrate processing method, and computer readable storage medium storing substrate processing program

Publication Date: 2015.05.26 TOKYO ELECTRON LTD

AI summary

Disclosed is a liquid processing apparatus capable of accurately determining a holding state of a substrate without being influenced by, for example, material or surface condition of a substrate. The liquid processing apparatus includes a substrate holding unit that holds a substrate, a camera that photographs a region where a peripheral edge portion of substrate is present when substrate is properly held by the substrate holding unit, and a control unit that determines a holding state of the substrate held by the substrate holding unit based on an image photographed by the camera.